You go away from the closer city and head out onto the long trek to the other one. Two days of traveling reveals a sign that says you are going to grue city.
> can I turn around?
No, I'm afraid not. you have to continue into grue city and hopefully you get lucky.
There is the city. there are no grues in sight. Sorry, you have o go. And you do. The city is vacant. You find five grue dollars and put them in your pocket. Then you find a match and a tank of gasoline.